PUBLICATION

Discontinuous organization and specification of the lateral floor plate in zebrafish

Authors
Schafer, M., Kinzel, D., and Winkler, C.
ID
ZDB-PUB-061020-47
Date
2007
Source
Developmental Biology   301(1): 117-129 (Journal)
Registered Authors
Schafer, Matthias, Winkler, Christoph
Keywords
Neural patterning, Floor plate formation, Hedgehog signaling, Nkx2.2, Homeobox genes
MeSH Terms
  • Animals
  • Base Sequence
  • Body Patterning*
  • DNA Primers
  • Gene Expression Profiling
  • Hedgehog Proteins/metabolism
  • Nervous System/embryology
  • Nervous System/metabolism
  • Receptors, Notch/genetics
  • Receptors, Notch/metabolism
  • Signal Transduction
  • Zebrafish
PubMed
17045256 Full text @ Dev. Biol.
Abstract
The floor plate is a signaling center in the ventral neural tube of vertebrates with important functions during neural patterning and axon guidance. It is composed of a centrally located medial floor plate (MFP) and a bilaterally positioned lateral floor plate (LFP). While the role of the MFP as source of signaling molecules like, e.g., Sonic Hedgehog (Shh) is well understood, the exact organization and function of the LFP are currently unclear. Based on expression analyses, the one cell wide LFP in zebrafish has been postulated to be a homogenous structure. We instead show that the zebrafish trunk LFP is discontinuously arranged. Single LFP cells alternate with p3 neuronal precursor cells, which develop V3 interneurons along the anteroposterior (AP) axis. Our mutant analyses indicate that both, formation of LFP and p3 cells require Delta-Notch signaling. Importantly, however, the two cell types are differentially regulated by Hedgehog (HH) and Nkx2.2 activities. This implicates a novel mechanism of neural tube patterning, in which distinct cell populations within one domain of the ventral neural tube are differently specified along the AP axis. We conclude that different levels of HH and Nkx2.2 activities are responsible for the alternating appearance of LFP and p3 neuronal progenitor cells in the zebrafish ventral neural tube.
Genes / Markers
Figures
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping